title: The circadian clock has transient plasticity of period and is required for timing of nocturnal processes in Arabidopsis.
abstract: A circadian rhythm matched to the phase and period of the day-night cycle has measurable benefits for land plants. We assessed the contribution of circadian period to the phasing of cellular events with the light : dark cycle. We also investigated the plasticity of circadian period within the Arabidopsis circadian oscillator. We monitored the circadian oscillator in wild-type and circadian period mutants under light : dark cycles of varying total duration. We also investigated changes in oscillator dynamics during and after the transition from light : dark cycles to free running conditions. Under light : dark cycles, dawn and dusk were anticipated differently when the circadian period was not resonant with the environmental period ('T cycle'). Entrainment to T cycles differing from the free-running period caused a short-term alteration in oscillator period. The transient plasticity of period was described by existing mathematical models of the Arabidopsis circadian network. We conclude that a circadian period resonant with the period of the environment is particularly important for anticipation of dawn and the timing of nocturnal events; and there is short-term and transient plasticity of period of the Arabidopsis circadian network.
authors.affiliation: School of Biological Sciences, University of Bristol, Bristol, BS8 1UG, UK.
authors.forename: Antony N
authors.initials: AN
authors.lastname: Dodd
authors.affiliation: Microsoft Research, 21 Station Road, Cambridge, CB1 2FB, UK.
authors.forename: Neil
authors.initials: N
authors.lastname: Dalchau
authors.affiliation: School of Life and Environmental Sciences, Deakin University, Geelong, Vic., 3220, Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Gardner
authors.affiliation: Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK.
authors.forename: Seong-Jin
authors.initials: SJ
authors.lastname: Baek
authors.affiliation: Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK.
authors.forename: Alex A R
authors.initials: AAR
authors.lastname: Webb
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D057906:Circadian Clocks / Q000235:genetics; D002940:Circadian Rhythm / Q000235:genetics; D017343:Genes, Plant; D008027:Light; D009154:Mutation; D017440:Photoperiod; D018521:Plant Physiological Phenomena / Q000235:genetics
keywords: Arabidopsis thaliana; circadian rhythms; environmental adaptation; signal transduction; systems biology